The present disclosure relates to a nonaqueous electrolyte and to a nonaqueous electrolyte battery, and more specifically relates to a nonaqueous electrolyte containing an organic solvent and an electrolyte salt and to a nonaqueous electrolyte battery using the same.
In recent years, portable electronic appliances such as a camera-integrated VTR (video tape recorder), a mobile phone and a laptop personal computer have widely spread, and it is strongly demanded to realize downsizing, weight reduction and long life thereof. Following this, the development of batteries as a portable power source for electronic appliances, in particular, secondary batteries which are lightweight and from which a high energy density is obtainable is advanced.
Above all, secondary batteries utilizing intercalation and deintercalation of lithium (Li) for a charge/discharge reaction (so-called lithium ion secondary batteries) are widely put into practical use because a high energy density is obtainable as compared with conventional lead batteries and nickel-cadmium batteries which are a nonaqueous electrolytic solution secondary battery. Such a lithium ion secondary battery is provided with an electrolyte together with a positive electrode and a negative electrode.
In particular, laminated batteries using an aluminum laminated film for a package member have a large energy density because of their light weight. Also, in the laminated batteries, when a nonaqueous electrolytic solution is swollen into a polymer, deformation of the laminated battery can be suppressed, and therefore, a laminated polymer battery is also widely used.
However, in the laminated battery, since the package member is soft, there was involved such a problem that the battery is easy to cause blister by a gas generated in the inside of the battery at the time of initial charge and also at the time of high-temperature storage. In response to this problem, as described in Patent Document 1 (JP-A-2006-86058), by adding a halogenated cyclic carbonate such as fluoroethylene carbonate or a cyclic carbonate having a carbon-carbon multiple bond such as vinylene carbonate to a nonaqueous electrolytic solution, a reaction of a negative electrode active material with the nonaqueous electrolytic solution, or the like is suppressed, whereby the battery blister at the time of initial charge can be suppressed. But, such a reactive cyclic carbonate was unable to suppress the battery blister at the time of use at a high temperature.
Also, Patent Document 2 (JP-A-2002-289188) proposes to use, as an electrode active material, a heteropolyacid salt which is a compound capable of intercalating and deintercalating a lithium ion and takes a relatively stable structure.